Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 101,856	$ 101,913
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of investment premiums, net	10,114	12,011
Gain on sale of investment securities, net	(858)	(135)
Gain on sale of other real estate owned, net	(1,530)	(193)
Valuation adjustment on other real estate owned	1,462	2,487
Provision for loan and lease losses	15,412	23,891
Change in cash surrender value of bank owned life insurance	(4,366)	(5,439)
Depreciation, amortization and accretion	30,059	24,411
Loss on sale of premises and equipment	4,211	2,481
Additions to residential mortgage servicing rights carried at fair value	(14,843)	(20,101)
Change in fair value of residential mortgage servicing rights carried at fair value	34,565	10,154
Change in junior subordinated debentures carried at fair value	3,203	2,920
Stock-based compensation	5,245	7,985
Net increase in trading account assets	(602)	(6)
Gain on sale of loans	(80,169)	(77,395)
Change in loans held for sale carried at fair value	(13,809)	282
Origination of loans held for sale	(1,810,425)	(1,859,380)
Proceeds from sales of loans held for sale	1,972,727	1,794,637
Goodwill impairment	142	0
Change in other assets and liabilities:
Net (increase) decrease in other assets	(16,958)	57,791
Net increase in other liabilities	57,836	4,468
Net cash provided by operating activities	293,272	82,782
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of investment securities available for sale	(247,620)	(619,131)
Proceeds from investment securities available for sale	319,919	337,088
Proceeds from investment securities held to maturity	282	344
Purchases of restricted equity securities	(600)	0
Redemption of restricted equity securities	7	72,417
Net change in loans and leases	(1,084,966)	(817,613)
Proceeds from sales of loans	311,669	164,868
Net change in premises and equipment	(15,572)	(42,580)
Proceeds from bank owned life insurance death benefits	814	4,184
Proceeds from sales of other real estate owned	10,228	15,187
Net cash used in investing activities	(705,839)	(885,236)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase in deposit liabilities	552,670	255,823
Net increase in securities sold under agreements to repurchase	55,674	12,390
Proceeds from term debt borrowings	285,000	0
Repayment of term debt borrowings	(270,015)	(114,999)
Dividends paid on common stock	(70,528)	(66,235)
Proceeds from stock options exercised	778	1,558
Repurchase and retirement of common stock	(9,374)	(11,307)
Net cash provided by financing activities	544,205	77,230
Net increase (decrease) in cash and cash equivalents	131,638	(725,224)
Cash and cash equivalents, beginning of period	773,725	1,605,171
Cash and cash equivalents, end of period	905,363	879,947
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Interest	35,820	33,054
Income taxes	12,851	17,223
SUPPLEMENTAL DISCLOSURE OF NONCASH INVESTING AND FINANCING ACTIVITIES:
Change in unrealized gains on investment securities available for sale, net of taxes	25,218	(7,019)
Cash dividend declared on common stock and payable after period-end	35,296	33,098
Transfer of loans to loans held for sale	265,741	0
Change in GNMA mortgage loans recognized due to repurchase option	(7,881)	3,493
Transfer of loans to other real estate owned	4,546	2,577
Transfers from other real estate owned to loans due to internal financing	$ 256	$ 0